Listen now (31 min) | In December it was announced that the Lawrence Livermore National Laboratory National Ignition facility has achieved its first goal of “Ignition”, in which 192 powerful lasers focused on a small pellet of fuel led to a sustained fusion reaction for a fraction of a second that released more energy than it received from the incident laser light. Following on requests from many readers, I describe the science behind this experiment, and the wishful thinking associated with it, regarding the possible use of fusion as an unlimited power source for humanity in the future.